The subject matter described herein relates generally to wind turbines and, more particularly, to a method and system for operating a wind turbine.
Wind turbines generally include a rotor having multiple blades that are attached to a rotatable hub. The rotor transforms wind energy into a rotational torque that drives one or more shafts. Often, the shafts are rotatably coupled to a gearbox that steps up the inherently low rotational speed of the rotor. The gearbox rotates a high speed shaft that drives a generator to produce electrical power, which is fed into a utility grid or to another destination.
At least some known gearboxes require lubrication to function effectively. Typically, a pump transports lubrication oil to the gearbox, and a sump collects the lubrication oil after the gearbox has been lubricated. In cold environments, the lubrication oil may become viscous and resistant to flow. In such environments, one or more heaters may be used to heat the lubrication oil to maintain a sufficient viscosity of the lubrication oil during operation.
If a wind turbine is idle for an extended period of time, the lubrication oil may need to be heated before the wind turbine resumes operation. In some known wind turbines, the heating of the lubrication oil may take between 6 and 8 hours, or longer. In such situations, a wind turbine may be unavailable to generate power while the lubrication oil is being heated, and significant revenue may be lost.